Launcher API

The Launcher API runs on the local Multilogin X Agent and handles browser profile lifecycle operations.

Base URL: https://launcher.mlx.yt:45001

WARNING

The Multilogin X Agent must be installed and running for these endpoints to work.

Start Browser Profile

GET /api/v1/profile/f/:folder_id/p/:profile_id/start

Start a browser profile. Optionally specify automation type for Selenium/Playwright/Puppeteer integration.

Parameter	Location	Required	Description
folder_id	path	Yes	UUID of the folder containing the profile
profile_id	path	Yes	UUID of the profile to start
automation_type	query	No	selenium, playwright, or puppeteer
headless_mode	query	No	true to start headless

# Start with Selenium automation
curl "https://launcher.mlx.yt:45001/api/v1/profile/f/FOLDER_ID/p/PROFILE_ID/start?automation_type=selenium" \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Accept: application/json"

Response (returns Selenium port in message):

{
  "status": {
    "error_code": "",
    "http_code": 200,
    "message": "54499"
  }
}

---

Start Quick Profile

GET /api/v1/profile/quick/start

Start a temporary quick profile that is not saved after closing.

Parameter	Location	Required	Default	Description
profile_name	query	Yes		Name for the quick profile
browser_type	query	No	mimic	mimic or stealthfox
os_type	query	No	windows	windows, macos, linux, android
automation_type	query	No		selenium, playwright, puppeteer
is_headless	query	No	false	Run headless
folder_id	query	Yes		UUID of target folder

curl "https://launcher.mlx.yt:45001/api/v1/profile/quick/start?profile_name=temp-profile&browser_type=mimic&folder_id=FOLDER_ID" \
  -H "Authorization: Bearer YOUR_TOKEN"

---

Stop Browser Profile

GET /api/v1/profile/stop/p/:profile_id

Stop a running browser profile.

curl "https://launcher.mlx.yt:45001/api/v1/profile/stop/p/PROFILE_ID" \
  -H "Authorization: Bearer YOUR_TOKEN"

---

Stop All Profiles

GET /api/v1/profile/stop/all

Stop all currently running browser profiles.

curl "https://launcher.mlx.yt:45001/api/v1/profile/stop/all" \
  -H "Authorization: Bearer YOUR_TOKEN"

---

Get Active Profiles

GET /api/v1/profile/active

Returns a list of currently running browser profiles.

curl "https://launcher.mlx.yt:45001/api/v1/profile/active" \
  -H "Authorization: Bearer YOUR_TOKEN"

---

Get Profile by WebSocket Debugger URL

GET /api/v1/profile/p/:profile_id/ws_debugger_url

Get the Chrome DevTools Protocol WebSocket debugger URL for a running profile.

curl "https://launcher.mlx.yt:45001/api/v1/profile/p/PROFILE_ID/ws_debugger_url" \
  -H "Authorization: Bearer YOUR_TOKEN"

---

Lifecycle Flow

Headless Mode

Start profiles without a visible browser window:

curl "https://launcher.mlx.yt:45001/api/v1/profile/f/FOLDER_ID/p/PROFILE_ID/start?automation_type=selenium&headless_mode=true" \
  -H "Authorization: Bearer YOUR_TOKEN"

Common Launcher Errors

Error	Cause	Solution
Connection refused	Agent not running	Start the Multilogin X Agent
Profile already running	Duplicate start	Stop the profile first, then restart
Invalid folder/profile ID	Wrong UUID	Verify IDs via Cloud API
Port conflict	Port in use	The agent assigns ports dynamically